package org.lk.reggie.controller;

import org.lk.reggie.common.R;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

@RestController
@RequestMapping("/common")
public class CommonController
{

    @Value("${reggie.path}")
    private String basePath;

    @PostMapping("/upload")
    public R<String> upload(MultipartFile file)
    {
        // file 是一个临时文件，需转存到指定位置，否则本次请求完成后临时文件会删除


        // 原始文件名
        String fileName = file.getOriginalFilename();

        String suffix = fileName.substring(fileName.lastIndexOf("."));
        // 使用 uuid 重新生成文件名，防止文件名重复造成文件覆盖
        fileName = UUID.randomUUID().toString() + suffix;

        File baseFile = new File(basePath);
        if (!baseFile.exists())
            baseFile.mkdirs();
        // 将临时文件转存
        try {
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(fileName);
    }


    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response)
    {
        // 设置相应格式
        response.setContentType("image/jpeg");

        // 输入流，通过输入流读取文件内容
        try {
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));
            // 输出流，通过输出流将文件写回浏览器
            ServletOutputStream outputStream = response.getOutputStream();

            int len = 0;
            byte[] b = new byte[1024];

            while ((len = fileInputStream.read(b)) != -1)
            {
                outputStream.write(b, 0 ,len);
                outputStream.flush();
            }

            outputStream.close();
            fileInputStream.close();


        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}
